Histological evaluation of biopsies in premenopausal patients with breast cancer will be done: 1) in search of precancerous lesions; 2) to determine type and extension of tumor and 3) to evaluate histologic factors that may predict outcome, and 4) to compare histologic changes with those of elderly females. Prognostic markers, such as cerb-2, p53 and nm23 will be studied by immunohistochemistry and in situ hybridization in order to determine their role in prognosis and to compare them with breast cancer in the elderly population.